1. Field of the Invention
The present invention pertains to a method of measuring multiphase (liquid and gas) fluid flow based on pressure and temperature measurements taken across a pump which is pumping the multiphase fluid and based on the power input to the pump.
2. Background
My U.S. Pat. Nos. 4,852,395, issued Aug. 1, 1989, and 5,244,372, issued Jul. 6, 1993, both assigned to the assignee of the present invention, pertain to multiphase fluid flowmeters for measuring mixtures of gas, oil and water, for example, with a high degree of accuracy. In certain flowmeter applications, such as surface and subsea oil production wells and similar flow measuring requirements, the degree of accuracy required for the flow rates of the various fluid components is not as great as that provided for by the meters described in the above-mentioned patents. Moreover, in certain fluid flow measuring applications, such as remotely located and subsea oil production wells, the placement of a complex flowmeter in the production fluid flowline is difficult and expensive.
On the other hand, in many instances multiphase fluids require to be transferred by mechanical pumps, such as in crude oil production operations. The present invention provides an improved flow measurement method which utilizes measurements taken of multiphase fluid flow through a pump including power input to the pump. The method provides a suitable degree of accuracy which may be used as the primary fluid flow measurement technique in many fluid flow measuring applications.